From 4c9353a5840b285631a86a5bad2b48ea6276abf3 Mon Sep 17 00:00:00 2001 From: Eli Zaretskii Date: Sun, 2 Jul 2017 18:01:39 +0300 Subject: [PATCH] Avoid off-by-one errors in column C-n/C-p calculations * src/indent.c (Fvertical_motion): Help C-n/C-p estimate correctly the width used up by line numbers by looking near the window-start point. --- src/indent.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/src/indent.c b/src/indent.c index adecc3622a8..2cacfbbe3c0 100644 --- a/src/indent.c +++ b/src/indent.c @@ -2068,9 +2068,26 @@ whether or not it is currently displayed in some window. */) start_x = window_column_x (w, window, start_col, cur_col); } - itdata = bidi_shelve_cache (); + /* When displaying line numbers, we need to prime IT's + lnum_width with the value calculated at window's start, since + that's what normal window redisplay does. Otherwise C-n/C-p + will sometimes err by one column. */ + int lnum_width = 0; + if (!NILP (Vdisplay_line_numbers) + && !EQ (Vdisplay_line_numbers, Qvisual)) + { + struct text_pos wstart; + SET_TEXT_POS_FROM_MARKER (wstart, w->start); + itdata = bidi_shelve_cache (); + start_display (&it, w, wstart); + move_it_by_lines (&it, 1); + lnum_width = it.lnum_width; + bidi_unshelve_cache (itdata, 0); + } SET_TEXT_POS (pt, PT, PT_BYTE); + itdata = bidi_shelve_cache (); start_display (&it, w, pt); + it.lnum_width = lnum_width; first_x = it.first_visible_x; it_start = IT_CHARPOS (it); -- 2.39.2